efsa-opinion-chromium-food-drinking-water
efsa-opinion-chromium-food-drinking-water
efsa-opinion-chromium-food-drinking-water
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
4.2.2.1. Data collection on <strong>food</strong> (excluding <strong>drinking</strong> <strong>water</strong>)<br />
Chromium in <strong>food</strong> and <strong>drinking</strong> <strong>water</strong><br />
Before applying any data quality criteria 27 138 analytical results on <strong>chromium</strong> were reported on <strong>food</strong><br />
(17 958 as unspecified <strong>chromium</strong>, 9176 as total <strong>chromium</strong> and four as <strong>chromium</strong> and derivatives). No<br />
data on <strong>chromium</strong> speciation were reported.<br />
Based on the evidence discussed in Section 4.1. the CONTAM Panel decided to assume that<br />
<strong>chromium</strong> analytical data reported in <strong>food</strong> refer to Cr(III). However, certain <strong>food</strong>s are prepared with<br />
<strong>water</strong> to be consumed (coffee, tea infusions, and dry infant and follow-on <strong>food</strong>), and an incomplete<br />
reduction of the Cr(VI) present in this <strong>water</strong> into Cr(III) may happen if the <strong>food</strong>s are ingested<br />
immediately after their preparation. In these cases, the occurrence data on Cr(III) reported for dry<br />
<strong>food</strong>s were used to estimate the exposure to Cr(III) while the occurrence data on Cr(VI) reported for<br />
different types of <strong>drinking</strong> <strong>water</strong> were used to estimate the exposure to Cr(VI).<br />
Of the reported data, 64 results were not considered for dietary exposure assessment as they belonged<br />
to the category ‘Grain as crops’, whose final use is unknown. Then, samples reporting neither LOD<br />
nor LOQ values were excluded together with those reported as ‘suspect samples’ related to the<br />
sampling strategy (939 and 337 samples, respectively). Finally, ten samples with exceptionally high<br />
concentrations of <strong>chromium</strong> as compared with the rest of the samples in the same <strong>food</strong> category were<br />
excluded (2-3 orders of magnitude higher). They were two samples of ‘Grains and grain-based<br />
products’, one unspecified (12 100 g/kg) and one of ‘Wheat rolls, white’ (13 500 g/kg), and eight<br />
samples of beer with reported values between 5100 and 9000 g/kg. The decision to exclude the eight<br />
samples of beer was based on diverse pieces of evidence. The reported values were three orders of<br />
magnitude higher than those reported for the rest of the samples in the <strong>food</strong> category ‘Beer and beerrelated<br />
beverage’ (average value of this category = 8.3 g/kg, n = 493). This average value was similar<br />
to those reported in the literature for the presence of <strong>chromium</strong> in beer, 0.48-56 g/kg (Anderson and<br />
Bryden, 1983), 0.6-13.6 g/kg (Kovács et al., 2007) or 6-8 g/kg (Reczajska et al., 2005). Based on<br />
this, and the fact that no plausible explanation for the high concentrations was found and the data<br />
provider could not confirm these eight analytical results, it was decided to exclude the eight samples<br />
of beer from the final dataset.<br />
After these steps a total of 25 788 analytical results remained in the database.<br />
Almost 50 % of the results were left-censored data and, therefore, special attention should be paid to<br />
the LODs and LOQs reported. To avoid overestimation of the exposure calculations at the upper<br />
bound (UB) and underestimation at the lower bound (LB) it was decided to establish a cut-off value<br />
for the reported LOQs above which samples were excluded from the final dataset. In order to establish<br />
an appropriate LOQ cut-off the distribution of the LOQs reported for the different <strong>food</strong>s at different<br />
FoodEx levels was evaluated (FoodEx levels 1, 2 and 3). Those analytical results, within one specific<br />
<strong>food</strong> category and at the selected FoodEx level, that reported LOQs above the 95 th percentile of the<br />
LOQ distribution were excluded. In Table 5 are shown the different cut-offs selected for the different<br />
<strong>food</strong> groups. It can be seen that in most of the cases the cut-off was applied at FoodEx level 1.<br />
However, specific cut-offs were applied for some specific <strong>food</strong> groups at FoodEx level 2 and 3 when<br />
needed (Table 5). In addition, an exception was made for the <strong>food</strong> category ‘Food for infants and<br />
small children’. For this category, the LOQ cut-off selected was the 75 th percentile (50 g/kg) instead<br />
of the 95 th percentile (1000 g/kg) as the samples with LOQ = 1000 g/kg were all left-censored data.<br />
The exclusion of these data avoided the bias of the occurrence values in this <strong>food</strong> category since the<br />
quantified values showed average <strong>chromium</strong> concentrations of 75 g/kg.<br />
Following this approach a total of 1 159 analytical results were excluded (4.5 % of the total), among<br />
them 226 corresponding to the <strong>food</strong> groups ‘Vegetable and vegetable products (including fungi)’ and<br />
‘Starchy roots and tubers’. Among the excluded samples only 110 were quantified results.<br />
EFSA Journal 2014;12(3):3595 37